Purpose
The aim of this study was to describe a modified surgical technique of an extended subscleral tunnel (ESST) with adjunctive application of mitomycin-C (MMC) and to evaluate its safety and efficacy in long-term intraocular pressure (IOP) control in glaucoma patients.
Patients and methods
This was a randomized-controlled prospective clinical trial that included 54 eyes of 46 patients diagnosed with primary open-angle glaucoma. They were divided into two equal groups: the 'trabeculectomy with adjunctive MMC' treatment, group A, and the 'modified trabeculectomy with adjunctive MMC and ESST' treatment, group B. Ultrasonic biomicroscopy measurement of the aqueous drainage route was performed at 12 and 24 months postoperatively. The main outcome results included the cumulative probability of surgical success, IOP values, and the number of antiglaucoma drugs needed.
Results
Group B achieved a cumulative probability of complete success of 0.68 and qualified success of 0.96 at the end of the 24-month study period; however, group A achieved a cumulative probability of complete success of 0.44 and qualified success of 0.84. Group B succeeded in achieving lower mean IOP values than group A, with fewer antiglaucoma drugs at all postoperative visits, but this was not statistically significant (P > 0.05). The aqueous drainage route was always larger in group B and there was a statistically significant decrease in its size only in group A (P = 0.036). Group B achieved statistically significant fewer early and late postoperative complications and also required fewer additional interventions compared with group A (P = 0.029). No significant adverse effects were caused by this modified combined technique.
Conclusion
Modified trabeculectomy with ESST combined with adjunctive MMC could be an efficient, safe, familiar, and applicable treatment technique for a successful trabeculectomy. It may provide a favorable long-term outcome, representing a simple novel way of performing successful glaucoma surgery.